With the occurrence of the current energy crisis, a shortage of liquid hydrocarbon fuels has been noted. Transportation is heavily dependent on liquid fossil fuels, as are home and industrial furnaces.
Fuels derived in whole or in part from biomass have recently become increasingly attractive. Biomass material has been transformed into methanol by pyrolysis and catalytic recombination, or ethanol by hydrolysis, fermentation, and distillation. The alcohol is then used as a blend with standard fuel in unmodified engines, or pure in engines which have been modified.
However, the large expenditure of energy generally deemed necessary to produce alcohol from raw biomass, and the inherent inefficiency of the typical fermentation process raises the question as to whether or not much energy is saved. Additionally, cost factors such as capital generally accepted as needed for processing plants and operating expenses of the fermentation and distillation plants may limit the economic savings of substituting alcohol for fossil fuel. It would be an advancement of the art to find a biomass-derived fuel which reduces the amount of "formation" energy that is typically required for producing alcohols. It would also be desirable if the fuel could be used with existing burners and transportation systems.
The present invention provides a fluid composition comprised of one or more water-soluble carbohydrates, one or more alcohols having less than four carbons, and water. This composition is essentially derived from biomass, and is superior to known biomass fuels because the amount of energy necessary to obtain water-soluble carbohydrates, or convert insoluble carbohydrates to soluble ones, is far less than that required for producing alcohols. For example, a sugar such as sucrose may be either directly obtained from biomass, or insoluble carbohydrates e.g., cellulose or starch, may be hydrolyzed to yield the sugar. In either case, the expenditure of energy is minimal. A simple alcohol (in limited concentration) would also be obtained from the biomass. The combination of water-soluble carbohydrates and alcohols requires less energy for its production than mere alcohol alone, and in the liquid phase the mixture is compatible with existing domestic and industrial furnaces. It is to be understood that alcohol may be produced from biomass by fermentation, or from coal or oil by synthesis for blending with carbohydrates in accordance with this invention. However, since the amount of alcohol produced would be less than in more conventional fuels where all the combustible component derived from biomass is alcohol, there would be an overall reduction in energy consumed in producing combustible fuel components from biomass in accordance with this invention.
Various fuel mixtures containing either carbohydrates, alcohols, or mixtures of both are known. In U.S. Pat. No. 1,527,144, issued to Frank E. Lichtenthaeler, a process for producing an alcohol-ether mixture directly from raw material containing sugars or starches and alcohol is disclosed. However, the final product does not contain a water-soluble carbohydrate such as a sugar. U.S. Pat. No. 3,393,059, issued to James E. Webb, with respect to an invention of James R. Mosler, discloses that honey may be added to a hydrocarbon fuel to control bacterial growth. Secondary effects of the honey include the trapping of dirt, water and other particulate matter entrained in the fuel; however, the specification fails to teach or suggest the inclusion of the honey as a fuel.
Gelled or semi-liquid fuel compositions comprising an alcohol, water, and a water-insoluble carbohydrate such as starch or cellulose serving as a gelling agent, are known. In U.S. Pat. No. 1,752,935, issued to Joseph A. Wyler, nitrostarch serves as the gelling agent for a solid and infusible alcohol fuel. In U.S. Pat. No. 1,995,911, issued to John Wysocki and William R. Rich, a fuel jelly is described which comprises an alcohol, water and a water-insoluble nitrocellulose solution. Finally, U.S. Pat. No. 2,613,142, issued to Sol B. Wiezer, discloses a fuel comprising alcohol, water and the gelling agent methyl cellulose.
However, none of the above teach or suggest that the proper combination of water-soluble carbohydrates such as sucrose, alcohols having less than four carbons, and water may be employed as a liquid fuel.